Control and feed mechanism for centering and drilling machines



March 19, 1957 L. FARNswoR'rH Re. 24

CONTROL AND FEED MECHANISM FOR CENTERING AND DRILLING MACHINES OriginalFiled Jan. 13, 1955 2 Sheets-Sheet 1 INVENTOR .L'dvpence firhswrfhAttorney March 19, 1957 L. FARNSWORTH Re. 24,

CONTROL AND FEED MECHANISM FOR CENTERING AND DRILLING MACHINES OriginalFiled Jan. 13, .1955 2 Sheets-Sheet 2 United States Patent CONTROL ANDFEED lVIECHANISM FOR CEN- TERING AND DRILLING IHACHINES LawrenceFarnsworth, Racine, Wis., assignor of fifty percent to Max Seft, Racine,Wis.

Original No. 2,732,737, dated January 31, 1956, Seriai No. 481,625,January 13, 1955. Application for reissue October 22, 1956, Serial No.617,673

15 Claims. (Cl. 77-18) Matter enclosed in heavy brackets appears in theoriginal patent but forms no part of this reissue specification; matterprinted in italics indicates the additions made by reissue.

This invention relates to centering and drilling machines of the typewherein the workpiece is rotatably driven and, more particularly, itrelates to an improved control and feed mechanism therefor.

The invention is in the nature of an improvement over the machineforming the subject matter of my co-pending United States applicationSerial Number 426,960, filed May 3, 1954, now Patent No. 2,732,735issued January 31, 1956. Machines of this type find particular utilityin centering and drilling the ends of small cylindrical workpieces, forexample, small electric motor shafts. The tolerances to which themachining of such shafts must be held are extremely close andmaintaining the proper concentricity of the centers and holes in theends of these shafts has been a very troublesome problem. With a machineof the type to which this invention pertains, it is possible tocompletely finish the external diameter of the workpiece beforecentering and drilling the ends. Furthermore, by rotating the workpieceand maintaining the tool stationary, concentricity can be held to veryclose limits, distortion of the ends eliminated, and breakage of thetools substantially reduced.

A general object of this invention is to provide an im proved centeringand drilling machine of the type in which the workpiece is rotatablydriven, which is highly efficient in performing the functions for whichit is designed.

Another object of this invention is to provide an improved controlmechanism for a centering and drilling machine of the above type, havinga single control lever capable of clamping the workpiece in operatingposition, positioning the drive mechanism to rotatably drive the piece,feeding the tool into operative engagement with the piece and actuatingthe lubricating means to supply a predetermined amount of lubricant.

Another object of this invention is to provide a highly compact andefficient centering and drilling machine having a control mechanismoperable by a single lever whereby the capacity of the machine isgreatly increased and operators fatigue reduced.

A still further object of this invention is to provide a new and novellubricating means for a centering and drilling machine which supplieslubricant to the tool in an eflicient manner at only the proper time inits cycle and in a predeterminable amount.

Other objects and advantages of this invention will become more apparentas this disclosure progresses, reference being had to the accompanyingdrawings, in which:

Figure 1 is an elevational front view of the machine embodying thisinvention.

Figure 2 is a perspective view taken from the left, rear side of themachine showing the control mechanism and lubricant supplying means,with parts broken away.

Figure 3 is a sectional view, on an enlarged scale, showing thelubricant supplying means.

Figure 4 is an elevational rear view of the valve for the lubricantsupplying means shown in Figure 3.

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Figure 5 is an exploded view, in section, of the valve taken on line 5-5of Figure 4.

Referring more particularly to the drawings, the main frame or supportstructure comprises spaced leg members 10, 11 secured together by bedplate 13. Table members 15, 16 are adjustably secured in alongitudinally arranged slot (not shown) in plate 13 and therebypositionable along the length thereof to accommodate workpieces ofvarious lengths. Table 15 has a longitudinally arranged groove along itstop surface in which is slidably secured the tailstock 17 by means of acap screw (not shown) extending through table 15 from the underside andinto a tapped hole in tailstock 17. A depth adjusting screw 19 isthreadably engaged in tailstock 17 and extends therethrough and a locknut 20 retains it securely in position. Rotatably mounted within thehead 22 of screw 19 is the stop member 24 which absorbs the thrust ofthe workpiece 25 bearing against it.

To the top surface 27 of table 16 is adjustably secured in groove 28 theheadstock 29 through which slid-ably extends, in a close fitting bore,the tool holder 31. Lockable within holder 31 is the non-rotatablecentering or drilling tool 32. As shown in Figure 2, a swinging arm 33is pivotally secured at one of its bifurcated ends by cap screw 34 to arearwardly extending ear portion 35 of headstock 29. A compound controlhandle 30 is pivotally secured to the other bifurcated end of arm 33 bythumb screw 33' and also pivotally secured intermediate its length totool holder 31 by thumb screw 31.

As seen in Figure l, the means for rotatably supporting the workpiece 25comprises two pairs of transversely aligned anti-friction supportingrollers 37, 38 (only the front roller of each pair being shown) mountedon the upper portions of tables 15, 16 respectively. The rollers aretransversely adjustable on their tables so as to accommodate variousdiameter workpieces. Reference may be had to my above identifiedco-pending application for a full description of these holders and theiradjusting means. However, it is sufficient to say here that these pairsof support rollers accurately support the workpiece while it isrotatably driven. In practice, workpiece speeds as high as 15,000 R. P.M. have been employed. An upper clamping roller 39, 40 is provided foreach pair of holding rollers 37, 38. Only one clamping roller 40 will bedescribed as the construction, support and actuation of clamping roller39 is identical. Roller 40, which is of the high-speed, anti-frictiontype, is rotatably mounted on the forward end of compound arm 41comprised of arm portions 42, 43 each pivoted on an upstanding portion44 of support structure 16 by means of thumb screw 45. Arm portions 42,43 may be considered as one integral arm 41 but the relative positionbetween arm portions 42, 43 may be varied as follows to accommodatedifferent diameter workpieces. A set screw 46 extends freely through ahole in arm portion 43 and is threadably engaged in arm portion 42. Anadjusting set screw 47 is threadably engaged in arm portion 43 and bearsagainst the upper surface of arm portion 42. When screw 46 is loosened,screw 47 may be adjusted to vary the distance of clamping roller 40 fromits corresponding support rollers 38 after which screw 46 is againtightened. This adjustment makes it possible for the clamping roller 40to bear firmly against the workpiece so as to hold it positively withoutany play and yet at the same time allows-it to be freely rotatable forbeing driven at high speeds. The lower end of arm 41 has rotatablysecured thereto a cam follower roller 48 by means of pin 49. Theclamping rollers 39, 40 are thus swung downwardly into operativeengagement with the workpiece or upwardly into an inoperative positionby the swinging of arms 41 about their screws 45.

Brackets 50, 51 which are secured to leg members 10,

11 respectively, rotatably support a main actuating member in the formof shaft 53. Rotatably secured on this shaft 53, for rotationthereabout, is the means for rotatably driving the cylindrical workpiece25. This driving means is also fully described in-my said co-pendingapplication and a brief description willsuffice here. A drive frame 55is rotatably mounted on shaft 53 at 56 and 57 andhas a fiat uppersurface 53 to which the electric motor 59 is secured by bolts 60. Themotor shaft 61 has a multiple V pulley, 62 over which is trained aplurality of flexible driving belts 63. Adjustably secured to anupstanding portion65 of drive frame 55 by means of arms 67, 68 aremultiple sheaves, 76, 71, respectively. Belts 63 are also trained over.sheaves 7h, '71 and in the driving position, that portion of the belts.between sheaves 70, 71 embrace a substantial portion of the periphery ofthe workpiece 25 to rotate it at a very high speed. This drivingpositionis obtained. when the drive frame 55 is rotated or swungforwardly about shaft 53 by means to be described.

At spaced locations on shaft 53 are secured two cams 73 (only one shown)one for each arm 41 of clamping rollers 39, 40. These earns 73 have apositioning surface 74' and a holding surface '75. As the. shaft 53 is.rotated in a counterclockwise, position, as viewed in Figure 2, therollers 39, 40; will bear against, the workpiece 25 at the time the camfollower 48 reaches the point on the cams 73 where surfaces 74 and 75intersect, assuming, of course, that the. adjusting screw 47has beenproperly set for the size of the workpiece involved. Continued rotationof shaft 53 causes cam follower to. ride on the cam holding surface '75which is formed as an arc whose center is the center of shaft 53.Therefore, clamping roller 40 is held firmly and positively with an evenamount of pressure against the workpiece as follower 4S rides on surface75 and is held thereon. It is while follower 48 is, moving along camholding surface 75 that the drive mechanism, lubricating means and toolfeed come into operation, in that order, as will appear presently.

A jointed linkage 77, 78 connects the portion of the ma n supportstructure 79 to a portion 80 of the drive frame 55. A stub shaft, 81 isrotatably secured to portion 84 and link 78 is rigidly fixed to thisshaft 81. Link 77 is pivotally attached, as at 82, to support structureportion 79 and pivotally connectedwith link 78 at 78". Link 77 is of Tshape having an upwardly. extending leg 77' to which is pivotallyattached link 83. An arm 84 is secured to shaft 53 for rotationtherewith and its bifurcated free end is pivotally secured to link 83.Thus, as shaft 53 rotates in a counter-clockwise direction from thatposition shown in Figure 2, link 83 will straighten. the linkage 77, 78to, a near dead center position so that it will lock the main shaft 53in operative position. This, movement has, swung drive frame 55upwardly, about shaft 53, and brought belts 63 into driving engagementwith the workpiece 25 as previously described. The sequence of theoperation of this arrangement is such that they drive belts 63 do. notcome into contact with the workpiece, until the clamping rollers 39, 40are in operative engagement with the workpiece, that is to say, untilthe cam follower 48 is bearing on the cam surface 7 5. in the reverseoperation, the locking rollers will not become disengaged from theworkpiece until the belts. 63 are free of the workpiece.

Compound control lever 36 comprises a. shaft rotating or a. mainactuating member section 86 having a handle portion 87 and a tool feedsection 88 having a bifurcated outer end portion 89. The shaft rotatingsection 86 is pivotally connected between bifurcated portion 89 by itsweb 90 atits underside and the connection is such that it allowsrelative movement between the sections 86, 88 in only a verticaldirection. Feed section 88 is pivotally connected, as previouslydescribed to tool holder 31 and swinging arm-33. Secured to shaft 53 atits right end is an arm 92 which is connected with shaft rotatingsection 86 4 at 93 by the rod 94. Swivel joint member 95, is pivotallyconnected to handle section 86 at 93 and to joint member 96, on the endof rod 94, at 97. Joint member 93 pivotally connects the other end ofrod 94 to the bifurcated part of arm 92 for swinging movement in eitherdirection.

The machine as shown in Figure 2 is in the inoperative position. Afterthe workpiece has been positioned on the pairs of supporting rollers 37,38 by the operator's left hand, which is free to load and unload themachine, the shaft rotating section 86 of control handle is swungupwardly to its limit in the horizontal position where it will remainunsupported by the operator due to'the supporting action of linkage 77,73 which has locked shaft 53 in the operating position. This upwardswinging of the control handle first serves to bring the clampingrollers 39, 40 into engagement with the workpiece, then swings the drivebelts 63 into engagement with the piece and at that time starts a flowof lubricant from the sump or oil pan 109 onto the tool 32 by thefollowing pump means.

Secured to the leg member 11 as at 102 is a cylinder 104 which isimmersed in the lubricant fluid. (not shown)v in drip pan 1%. Thecylinder 104 has; a slot 105- on, its upper side which extends alongpart of the cylinder length. A guide 107 is slidable in bore 193 and hassecured, there-v to, and extending through slot 105 an arm 109 having anaperture 110 in its upper end. Linkage means connects shaft 53 and guide107 and comprises a bifurcated member 112 secured to shaft 53 and a link113 pivotally connects member 112 with arm 109 of the guide 107. Guide107 has a bore extending through it in which is slidable a rod 115having a threaded portion at either end. Piston 118 and stop member 117.are threadably engagedon the, ends of rod 115 as shown in Figure 3. Acompression spring 120 is mounted over rod 115 between guide 107 and thepiston 118. An outlet connection is secured in a tapped holenear the endof cylinder 104, and has so,- cured to it a conduit 126 supported bypost 127 and terminating at 128, as shown in Figure 1, where the tool 32engages the workpiece.

The inlet for this pump comprises a disk 130 having a central bore 131through which extends the thumb screw 132 threadably engaged in thevalve plate 134. Disk 130 also has a series of fluid inlet apertures 136extending therethrough. Yieldable means in the form of a compression,spring 137 is mounted on screw 132 and serves to bias the valve plate134 againstdisk 130 and thereby seal the inlet openings 136. The disk130 is press fitted into the bore 108 and thus forms a tight fit.

When the piston is moved. to the left, as viewed in Figure 3, byrotation of shaft 53, this suction stroke lifts the valve plate againstthe action of spring 137, 01f of the disk 130 and fluid from sump 100 isdrawn into the cylinder. On the pumping stroke, the piston moving to theright effectively causes the fluid to seal plate 134 against disk 130.When shaft 53 is rotated, by lever section 86, from the position shownin Figure 2, themember 112, through link 113, forces the guide 107 tothe right. Due to the resistance of the oil in the cylinder the spring120 is compressed. and guide 107 slides over rod 115 and relative topiston 118. The spring 120 then gradually forces the piston 118 to theright until stop member 117 bears against guide 107', thus, forcinglubricant fluid out of the cylinder through conduit 126 and over thetool 32. With this arrangement, this retarded pumping action commencesbefore the tool engagesthe workpiece. and continues only for thecentering or drilling operation. The pumping rate. is of coursepredeterminable by'the compressive strength of the spring 120. Thelubricant, so discharged on the tool drains backinto pan 100 for reuse.

Summary A compound control handle is provided which is operable by onehand of the operator and leaves his other hand free to load, reverse theworkpiece, and unload the machine. The initial movement of the handleserves to clamp the workpiece in rotatable position, apply the drivingmeans to the piece, lock the main actuating shaft in operative positionand set the pump means in operation to supply a predetermined amount oflubricant at a given rate. At this time the operator shifts the lever 30to the left, as he faces the machine, to thereby feed the tool 32 intothe workpiece. Both movements of the control handle 30, i. e., theupward and leftward motions, are accomplished by an easy sweeping motionwhich is a simple and quick operation.

The conveniently located pump is simple in construction and is cocked bya simple movement of the guide 107 to discharge a given amount of oil ata certain rate and at precisely the proper time in each cycle of machineoperation.

In practice this machine has proved highly efficient, one operatorproducing as many as 900 finished shaft ends per hour within extremelyclose eccentricity tolerances.

What is desired to be secured by Letters Patent is:

1. In a machine having support structure for rotatably supporting adriven cylindrical workpiece; a pair of clamping rollers mounted on saidstructure for swinging between an inoperative and a workpiece clampingposition; drive means for said workpiece mounted on said structure forswinging between an inoperative and a workpiece driving position; afeedable tool mounted on said structure; said machine having a lubricantpump means adapted to discharge adjacent said tool; a main actuatingmember operatively mounted on said structure; connecting means betweensaid member and said clamping rollers adapted to swing said rollersbetween an inoperative and a workpiece clamping position upon movementof the member, lockable connection means between said member and saiddrive means adapted to swing said drive means upon movement of saidmember and lock said drive means in the workpiece driving position,second connecting means between said member and said pump means foractuating said pump means upon movement of said member; a leverpivotally connected with said structure and with said tool for shiftingthe latter, said lever also connected with said main actuating memberfor movement thereof.

2. A device as described in claim 1 further characterized in that saidlever comprises; a tool feeding section pivoted to said structure andsaid tool for movement therewith, an actuating member section pivotallyconnected with said tool feeding section and also connected with saidmember for actuating the latter.

3. In a centering and drilling machine having support structure forrotatably supporting a driven cylindrical workpiece; a pair of clampingrollers mounted on said structure for swinging between an inoperativeand a workpiece clamping position; drive means for said workpiecemounted on said structure for swinging between an inoperative and adriving position; a feedable tool mounted on said structure; saidmachine having a lubricant pump means adapted to discharge adjacent saidtool; a main actuating member rotatably mounted on said structure, meanssecured to said member for swinging said clamping rollers, second meansconnected between said member and drive means for swinging the latter,connecting means between said pump means and member adapted to actuatethe former when the latter is rotated; a compound lever having a feedsection pivotally mounted to said structure and said tool forpositioning the latter, said lever also having a member rotating sectionpivotally attached to said feed section and operatively connected withsaid member for rotating the latter.

4. A device as set forth in claim 3 further characterized in that saidpump means comprises, a cylinder, a piston slidable within saidcylinder, an inlet valve in said cylinder adapted to open on a suctionstroke of said piston and close on a pumping stroke, said lever having aconnection to said piston for actuation thereof.

5. In a machine having support structure for rotatably supporting adriven cylindrical workpiece; a pair of clamping rollers mounted on saidstructure for swinging between an inoperative and a workpiece lockingposition;

drive means for said workpiece mounted on said structure for swingingbetween an inoperative and a driving position; a tool slidably mountedon said structure and adapted to be positionable in an inoperative or aworkpiece engaging position; said machine having a lubricant pumpingmeans adapted to discharge adjacent said tool; a main actuating shaftrotatably mounted on said structure, means secured to said shaft forswinging said clamping rollers, second means connected between saidshaft and frame for swinging the latter, connecting means between saidpumping means and shaft adapted to activate the former when the latteris rotated; a compound lever having a feed section pivotally mounted tosaid structure and said tool for positioning the latter, said lever alsohaving a shaft rotating section pivotally attached to said feed sectionand operatively connected with said shaft for rotating the latter.

6. In a centering machine having support structure for rotatablysupporting a driven cylindrical workpiece; a pair of clamping rollersmounted on said structure for swinging between an inoperative and aworkpiece clamping position; flexible drive means for said workpiecemounted on said structure for swinging between an inoperative and aworkpiece driving position, a feedable tool mounted on said structureand a lubricant pumping means on said machine including a cylinderhaving a piston slidable therein, and adapted to discharge adjacent saidtool; a main actuating shaft rotatably mounted on said structure, cammeans secured to said shaft for swinging said clamping rollers, linkagemeans connected between said shaft and frame for swinging the latter,connecting link means between said piston and shaft adapted to shift theformer when the latter is rotated; a compound lever having a feedsection pivotally mounted to said structure and said tool forpositioning the latter, said lever also having a shaft rotating sectionpivotally attached to said feed section and operatively connected withsaid shaft for rotating the latter, whereby movement of the shaftrotating section will swing the clamping rollers and drive means intooperative engagement with said workpiece and actuate the pump means andsubsequent movement of said compound lever will position said tool inengagement with said workpiece.

7. A device as recited in claim 6 further characterized in that saidlinkage means comprises a pair of links pivotally connected togetherwhich are adapted to assume a substantially straight position to holdsaid shaft in operative position.

8. In a machine having a cutting tool and a control lever forpositioning said tool; lubricant pump means comprising, a cylinderhaving a guide slidable therein, means connecting said lever with saidguide for sliding the latter within said cylinder, a piston slidablyconnected to said guide for movement relative thereto, yieldable meansbetween said guide and said piston adapted to urge them apart wherebysaid piston delivers a. pumping stroke after said lever has slid saidguide, second means forming a fluid communication between said cylinderand said tool.

9. A device as defined in claim 8 further characterized in that saidmachine has a lubricant sump located directly beneath said tool forcatching lubricant passing thereover, said pump means mounted withinsaid sump, said second means comprising a fluid conduit connected at oneend with said cylinder and having its discharge end adjacent said tool.

10. In a machine having a support structure for rotatably supporting adriven cylindrical workpiece, a clamping roller mounted on saidstructure for swinging between, anmoperative, and a workpiececlampingp0,- sition;,flexib le drivemeans mountedon; said structure for swingingbetween an inoperativeand a workpiece driving position; as-feedabletqol-mounted on 'saidfstrucw time; said, machine also having a lubricantpump means adapted to discharge lubricant on said tool, amainactuatingmember operativbly mounted on saidstructure and connected withsaid clampingroller, said drive means, and said pump means, wherebyinitial'movement of said member in one directionwill swing said.clamping roller into workpiece clamping position and actuate said pumpand continued movement of said'membei; will swing said drive meansintoworl piece driving position; a compound control lever pivotallyconnected. with said structure and having an actuating section connectedwith said actuating member for operatingthelatter and also having a toolfeeding section for opera-tingsaid tool.

-1,-1. -A device as defined in claim further characterized in that saidtool feed section is pivoted tosaid structure and said actuating sectionis pivotally connected to said toolrfeed section. I

1-2. A device as defined in claim 10 further characterized in that saidpump means comprises; a cylinder,

a guide slidable within said cy-linder, apiston 'slidably connected tosaid guide for movement relative thereto, yieldable means between said-guide andsaid piston whereby-said piston delivers apumping stroke aftersaid guide has been moved/ 1-3.. In a machine having a support structurefor rotatably supporting a driven cylindrical workpiece and alsosupporting shiftable parts, a feedab'le tool holder slidably mountedon'said structure formovement toward and away from said workpiece andamain actuating member operatively mounted onsaid structure for actuatingsaid parts, the improvement comprising, a compound control, handlehaving a tool feed section pivotallyconnected between said, structureand said holder, said handle also having an. actuating section pivotallysecured to said feed section for swinging-in a substantially verticaldirection, linkage 'rneans connecting said member to said actuatingsection whereby when the latt'eris swung said member will be actuatedand when said handle is moved said holder will be slid. I

14. The structure defined in claim 13 further characterized in that saidtool feed section'is swingable in a substantially horizontal directionand said actuating section is pivoted on a substantially horizontal axiswhereby said sections swing in a substantially horizontal direction as arigid unit.

15. In a machine having a support structure for rotatably supporting adriven cylindrical workpiece, a feedable tool holder slidably mounted onsaid structure for movement toward and away from said workpiece, meansmounted on said structure to drivingly'embrace said work'- pieceand amainactuating member operatively'connected to said means for actuationthereof, the improvement comprising, a compound control fhandle having atool feed section pivotally connected between said structure and saidholder, said handle also having an actuating section pivotally securedto said feed section for swinging in a substantially vertical direction,linkage means connecting said member to said actuating section wherebywhen the latter is swung said member will be actuated and both saidsections are movable in a substantially horizontal direction as a rigidunit to slide said holder.

References (lites! in the file of this or the original patent UNITEDSTATES PATENTS patent

